Ultrasonic knife



FIG. 1 is a top, right side perspective view of an ultrasonic knife showing our new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is an enlarged view of area 8 encircled by broken lines in FIG. 6 ; and,

FIG. 9 is an enlarged view of area 9 encircled by broken lines in FIG. 3 .

The dash-dash broken lines in the drawings depict portions of the ultrasonic knife that form no part of the claimed design. The dot-dash broken lines shown in the figures are included to identify areas of enlargement and form no part of the claimed design. 

CLAIM The ornamental design for an ultrasonic knife, as shown and described. 